The subject matter disclosed herein relates generally to the field of unmanned aerial vehicles and, more particularly, to an adaptive multi-scale perception system and method for autonomous landing of an unmanned aerial vehicle.
Description of Related Art
Unmanned aerial vehicles (UAVs), for example, fixed-wing and rotorcraft UAVs, are powered aircraft without a human operator. As such, UAVs provide advantages over manned aircraft by removing humans from situations which may be deemed dangerous, for example, during reconnaissance or during search and rescue operations during a natural disaster. Autonomous UAVs are a natural extension of UAVs and do not require real-time control by a human operator. Autonomous UAVs may be required to land on an unprepared site or unknown terrain without human assistance during mission operation or in an emergency, must be able to autonomously select a desirable landing site, or must be able to autonomously identify and classify objects on the ground in order to be a viable and effective option in flight operations.
Current art on autonomous landing and object identification in autonomous vehicles has focused on three-dimension (3D) sensors, e.g., LIght Detection And Ranging scanners (LIDAR) and video sensors to sense the 3D environment and terrain types and to identify terrain semantics for target identification or safe landing area detection. As these conventional systems acquire data by using the same sensors throughout the perception process, limitations in perception range and resolution of sensors create an unnecessary waste of storage space, communication bandwidth, and processing power. Also, conventional systems use the same parameters, regardless of altitude or scale, in perception algorithm to process the acquired sensor data. As a result, the algorithms are not robust to scale change and appearance variations, for example, region segmentation, or semantic classification. Additionally, conventional systems using a single LIDAR approach are not able to discriminate a soft ground surface over a surface that can provide load bearing capability or small foreign objects in the aircrafts path while approaching a landing site